Video data frequently includes data, such as closed caption text data, that is transmitted during the vertical blanking interval (VBI). The closed caption text data is typically transmitted during line 21 of either the odd or even field of the video frame in a National Television Standards Committee (NTSC) format. Closed caption decoders strip the encoded text data from the video signal, decode the text data, and reformat the data for display, concurrent with the video data, on a television screen. Such closed caption decoders process the text data separately from a video signal.
It is desired to have a multimedia system or a PC system that digitally processes and displays both graphics and video data. It is desired to have the GUI accelerator process and store or display the closed caption data in a manner similar to the processing and storing processing of video data.